code: def positive_integer_or_none(value):
      """Ensure that the provided value is a positive integer or None.
  
      Parameters
      ----------
      value: string
          The number to evaluate
  
      Returns
      -------
      value: int or None
          Returns a positive integer or None
      """
      if value.lower() == "none":
          value = None
      else:
          try:
              value = int(value)
          except Exception:
              raise argparse.ArgumentTypeError(
                  "Invalid int value: '{}'".format(value)
              )
          if value < 0:
              raise argparse.ArgumentTypeError(
                  "Invalid positive int value: '{}'".format(value)
              )
      return value
  
file_path: tpot/tpot/driver.py
imports: import numpy
  import pandas
  import argparse
  from sklearn.model_selection import train_test_split
  import sys
  import os
  from importlib import import_module
  from .tpot import TPOTClassifier, TPOTRegressor
  from ._version import __version__
label_desc: Use image node_id 2 for calling a global function with example usage: positive_integer_or_none(value) and returns: value